Apparatus for casting metal alloys with low melting temperatures

Abstract

A metal casting process for producing melt-out metal cores and the like made of metal alloys with low melting temperatures achieves a casting with uniform density, high quality finish and a fine grain structure. The process and apparatus do not require the pre-pressurization of a charging cylinder and permit closed dies to be used. The apparatus comprises a molten metal alloy tank, a cylinder in the tank having at its base a connection to a passageway leading through the tank to a die located outside the tank. A valve is provided in the passageway, located in the tank having a first position where the passageway to the die is open and a second position where the passageway to the die is closed. In the second position, a valve port provides a connection from the cylinder to the molten metal alloy in the tank. A valve actuator moves the valve from the first to the second position, a piston within the cylinder and a power system raises the piston in the cylinder with the valve in the second position to fill the cylinder with molten metal alloy and lower the piston with the valve in the first position to inject molten metal into the die. In a preferred embodiment, a second valve is located outside the tank and in the passageway to the die. The second valve operates in conjunction with the first valve in the first position to allow the injection of molten metal alloy into the die.